Synthesis of Hierarchical Porous Carbon Monoliths with Incorporated Metal-Organic Frameworks for Enhancing Volumetric Based CO2 Capture Capability

This work aims to optimize the structural features of hierarchical porous carbon monolith (HCM) by incorporating the advantages of metal-organic frameworks (MOFs) (Cu-3(BTC)(2)) to maximize the volumetric based CO2 capture capability (CO2 capacity in cm(3) per cm(3) adsorbent), which is seriously required for the practical application of CO2 capture. The monolithic HCM was used as a matrix, in which Cu-3(BTC)(2) was in situ synthesized, to form HCM-Cu-3(BTC)(2) composites by a step-by-step impregnation and crystallization method. The resulted HCM-Cu-3(BTC)(2) composites, which retain the monolithic shape and exhibit unique hybrid structure features of both HCM and Cu-3(BTC)(2), show high CO2 uptake of 22.7 cm(3) cm(-3) on a volumetric basis. This value is nearly as twice as the uptake of original HCM. The dynamic gas separation measurement of HCM-Cu-3(BTC)(2), using 16% (v/v) CO2 in N-2 as feedstock, illustrates that CO2 can be easily separated from N-2 under the ambient conditions and achieves a high separation factor for CO2 over N-2) ranging from 67 to 100, reflecting a strongly competitive CO2 adsorption by the composite. A facile CO2 release can be realized by purging an argon flow through the fixed-bed adsorber at 25 degrees C, indicating the good regeneration ability.